1. Field of the Invention
The present invention relates to a novel zeolite composition and a method for its preparation.
2. Prior Art
Crystalline inorganic aluminosilicate zeolites occur naturally in a wide variety of crystallographic forms and have been successfully synthesized. These zeolites have a common structure characterized by a substantially rigid three-dimensional network system composed of silicon, aluminum and oxygen atoms arranged such that the crystals possess interstitial channels communicating with cavities. These channels may also contain cations such as sodium and calcium ions.
A wide variety of different catalytic and other properties have been found to be associated with crystalline aluminosilicates. They have found wide application in catalysis, drying procedures, purification, etc. They have also been found to be useful for promoting the oxidation of various compositions.
The catalytic properties of zeolites can be altered by introducing into the interstitial channels and cavities thereof one or a variety of catalytically active compositions. The catalysts are introduced into the zeolite after crystal formation of the aluminosilicate or are incorporated in the zeolite structure during manufacture of the crystalline material.
Zeolites have been previously modified to contain positively charged and neutral metal complexes (ML.sub.n.sup.2+ and ML.sub.n, wherein M is a metal ion, L is a neutral or charged ligand and n indicates the number of ligands bound to the metal ion). Because of the negative charges on the oxide surface and in the interstitial channels and cavities of the zeolite, it was thought to be impossible to incorporate anionic materials (ML.sub.n.sup.m-) wherein M, L and n are as described above and m- is the charge on the anionic ligand therein.
It is an object of the present invention to provide a new class of compositions comprising zeolite materials containing anionic complexes entrapped therein.
It is a further object of the present invention to provide a novel method for preparing the above-described zeolite composition containing entrapped anionic materials.